Mike Napoli reveals hip condition

Boston Red Sox first baseman Mike Napoli revealed Tuesday that he has avascular necrosis in both hips, the same degenerative condition that ended the career of two-sport star Bo Jackson.

But Napoli said that because the condition was discovered in its early stages and is being treated with medication, he sees no reason why he can't play this season.

Avascular necrosis, known by its acronym AVN and also known as osteonecrosis (ON), is a progressive, degenerative disorder that kills bone tissue.

Napoli has played seven years in the majors but said the condition was not discovered until he underwent a physical after agreeing to a three-year, $39 million contract with the Red Sox in early December.

"Obviously, it was a pretty tough offseason," Napoli said in a conference call Tuesday, adding it was a "shock" to him to learn of the AVN. "But we think we've got it figured out. We saw a bunch of doctors, got a bunch of opinions and went from there. I got on medication. There's no reason I shouldn't be healthy and ready to go for Opening Day."

Napoli's agent, Brian Grieper, said his client is asymptomatic.... He has every expectation of fully participating in spring training and being ready for Opening Day, Grieper said.

"There is no soreness, no restrictions, no nothing," Grieper said.

Dr. Joseph Lane of New York's Hospital for Special Surgery is overseeing Napoli's treatment. Both Grieper and Napoli said doctors could not tell them what caused the condition.

"The answer to that is we don't have an answer," Grieper said. "We don't know."